DES MOINES, Iowa (AP) — Police are trying to determine why a young Iowa mother killed her 2-year-old son and herself. Indianola and Des Moines police held a joint news conference Sunday about the deaths of 23-year-old Kelli Sly and her son, Gavin. Police say Sly killed Gavin inside their Indianola apartment sometime Sunday morning. Then Sly drove about 20 miles north to Des Moines where she crashed her vehicle into a bridge pillar and died. The crash happened around 8:30 a.m. Sunday, and Gavin Sly’s body was found about a half hour later. Indianola police say officers spoke to Kelli Sly Saturday because she violated a court order by contacting her estranged husband. Sly’s husband said then he worried she would hurt herself, but Sly denied being suicidal on Saturday.